Thermal cut-out



(No Model.)

G. H. WHITTINGHAM.

THERMAL CUT-OUT.

No. 452,152. Patented May 12,1891.

WITNESSES.-

UNITED STATES PATENT FFICE.

GEORGE HERBERT TVHITTINGIIAM, OF BALTIMORE, MARYLAND.

' THERMAL CUT-OUT.

SPECIFICATION forming part of Letters Patent No. 452,152, dated May 12,1891. Application filed October 18, 1890. Serial No. 368,538. (Nomodel.)

To all whom, it may concern:

Be it known that I, GEORGE HERBERT WHIT- TINGHAM, a citizen of theUnited States, and a resident of Baltimore city, in the State ofMaryland, have invented certain new and useful Improvements in ThermalOut-Outs, of which the following is a specification.

My invention relates to fuse cut-outs for incandescent lamps and otherpurposes where it is desired to introduce a fuse into an electricalcircuit.

In wiring for electrical lighting for incandescent lamps it is necessaryto protect the lamp from being destroyed by a current of great intensityby introducing into the circuit a fuse which will be melted by saidcurrent and the circuit destroyed. Many such devices have been designed;but the object of the invention which is the subject of this applicationis to cheapen construction by simplifying the structure, as well as tomake a cut-out device which can be quickly replaced when the fuse hasbeen burned by any one without the exercise of skill in electric wiringand withoutthe use of anyinstrument, not even a screw-driver.

In the drawings, Figure 1 represents a plan of my fuse, showing two fusedevices in the two positions of the apparatus, one with the fuse in thecircuit and the other with the fuseholder at right angles to its formerposition. Fig. 2 is aview of the bottom side of the fuseholder, showingthe fuse in position. Fig. 3 is a View of the top side of the same,showing the fuse in position. Fig. 4; is an end eleva tion of the same,showing fuse in position. Fig. 5 is a side elevation of the same,showing fuse in position. Fig. 6 is a side elevation of the device, withone of the contactbrushes and the bed in section through the line so 00,Fig. 1.

Referring to Figs. 1 and 6, 1 is a bed made, preferably, of porcelain,in the center of which is a circular indentation or socket of slightdepth, in which the fuse-holder rests and revolves. The fuse-holder 3 isa cup, of porcelain or other refractory material, provided with handle 4on the top. The cup is shaped in the form of two circles, whichintersect one another, so as to cause the ends of the cup to be convexand the sides concave where the circles intersect one another. The longdiameter of the cup is the same as the diam eter of the socket 2, sowhen the cup rests in said socket it will revolve therein and fitsnugly. The sides of the cup are provided with the concave indentationsfor the purpose of making points which will never be touched by thecontact-brushes, thereby avoiding the possibility of coating theexterior of the cup with metal rubbed from the brushes, and therebyforming a conductor from one brush to the other around the fuse. Theedges of the cup are provided with a slot 5, which is in the line of thegreater diameter of the cup, and which extends about two-thirds of thedepth of the sides of the cup. Upon the exterior of the cup at its endsand on opposite sides of the slot 5 the surface of the cup is cut awayat right angles with the slot 5 from the top of the cup toward its rim,leaving, however, a thin edge of the rim, which is of the full contourof the cup, forming the notches 0 6 on opposite ends of the cup and onopposite sides of the slot 5. This structure is shown plainly in Figs.41 and 6.

T is a section of fuse-ribbon, which is placed in the slot 5 across thecup, and the projecting ends are bent in opposite direction into thenotches 6 6, by which it is held in place.

8 S are contact-brushes secured to bindingposts 9 9, to which thecircuit wires are connected. The contact-brushes 8 S extend from thebinding-posts toward one another, their extremities standing over thesocket2 at such a distance apart that the cup 3 maybe inserted betweenthem when turned in the position shown on the right of Fig. 1, in whichthe shorter diameter of the cup is between the brushes, and they do nottouch it on either side. The brushes are made of metal having someelasticity, so that when the cup is turned between them by the handle athey will be pressed apart by the ends of the cup and will exert apressure upon said ends. \Vhen the cup is turned so as to place thelonger diameter of the cup between the extremities of the brushes, theywill fall into the notches 6 6 and upon the ends of the fuse 7, whichlie in said notches, thereby establishing a circuit between said brushesor contact-strips through the fuse 7. If now the A quarter-turn of thecup from the position shown on the left of Fig. l to the position shownon the right of Fig. 1 will release the cup from the hold of thebrushes, and it may be taken from its socket and a fresh piece of fuseinserted into the slot 5, the ends being bent, as before described, inopposite directions into the notches 6 6. The cup is then replacedintothe socket? in the position shown on the right of Fig. 1 and given aquarter-turn by its handle into the position shown on the left of Fig.1, in which position, as before stated, the brushes 8 S will be incontact with the turned-over ends of fuse '7; but the circuit will bere-established without injury to the socket or without taking theapparatus apart otherwise than to remove the cup. The brushes 8 8 restupon the bed 1 and stand over the socket 2. The rim of the cup below thenotches 6 6 is of such a width that when the cup is inserted in thesocket the upper side of said rim will be on the level of the surface ofthe bed 1. Thus when the cup is turned from the position shown 011 theright of Fig. 1 to the position shown on the left of Fig. 1, and thebrushes fall into the notches 6 (3, the ends of said brushes will standupon the rim and hold the cup firmly in the socket.

The bed and cup being made of porcelain, it is unnecessary to providethe device with any supplemental cover, because the fuse is inclosedwithin the cup and is surrounded 011 all sides by porcelain; or othersimilar mate rial may be used, if preferred.

Having thus described my invention, what I desire to claim by LettersPatent is 1. In a thermal cut-out, the combination of a cup ofrefractory material, the edge of which is slotted, with abase of similarmaterial having a socket circular in form and of the same diameter asthe cup, into which the cup when inverted fits and may revolve, asection of fuse-ribbon inserted in the slot of the cup, the projectingends thereof being bent over in contact with the exterior of the cup,and strips or brushes connected to the terminals of an electric circuit,which, when the cup is pressed between them, will make contact with theturned-over ends of the fuse and complete the circuit through said fuse,substantially as described.

2. In a thermal cut-out, the combination of a cup of refractory materialof greater diameterin length than width and having indentations in thesides thereof, and the edge of the cup slotted in the line of its longerdiameter, with a base of similar material having a circular socket ofthe same diameter as the longer diameter of the cup, in which the on p,when inverted, fits and may revolve, a section of fuse-ribboninserted insaid slot in the cup-rim and havingits projecting ends turned over incontact with the exterior of the cup, and contact strips or brushesconnected to the terminals of an electric circuit, which, when thelongerdiameter of the cup is pressed between them, will make contact with theturned-over ends of the fuse and complete the circuit through said fuse.

3. In a thermal cut-out, the combination of a cup of refractory materialof greater diameter in length than width and having its rim slotted inthe line of its greater diameter, with a fuse-ribbon inserted in saidslot, the projecting ends thereof being bent over in contact with theexterior of the cup, and contact-strips connected to the terminals of anelectric circuit, so located that the distance between their extremitieswill be less than the greater diameter of the cup, but greater than theshorter diameter, so that when the cup is revolved between them theywill come into contact with the ends of the cup and the extremities ofthe fuse which projects therefrom, but will not touch the sides whenthey are turned toward said con tact-strips, substantially as described.

et. In a thermal cut-out, the combination of a cup of refractorymaterial of greater diameter in length than width and having its rimslotted in the line of its greater diameter, and provided on theexterior at its ends and on opposite sides of the slot with notcheswhich are below the rim, with a fuse-ribbon inserted in said slot andhaving its projecting ends turned over in opposite directions into thenotches, and contact-strips connected to the terminals of an electriccircuit, so located that the distance between their extremities will beless than the greater diameter of the cup, but greater than the shorterdiameter, so that when the cup is revolved between them they will comeinto contact with the ends of the cup and fallinto the notches thereinand upon the extremities of the fuse which lie in said notches, but willnot touch the sides when they are turned toward said contactstrips,substantially as described.

GEORGE HERBERT Wlll'l"llNGlIA]l.

IVitnesses:

M. TURNER, II. MAoCARrHv.

